A large number of reinforced tubing devices have been introduced for use in a wide variety of applications. For example, flexible reinforced tubing is commonly used to transmit translational motion (i.e., push-pull) or rotational motion (i.e., torque) from a control apparatus to an object located distally which is to be manipulated or moved. An example of one such device is the reinforced tubing disclosed in U.S. Pat. No. 5,101,682, which can be used in medical applications and includes a surrounding layer of electroplated material covering and bonded to the tube. Another example of a reinforced tubing device is disclosed in U.S. Pat. No. 3,769,813 for a resilient torque tube that is reinforced with alternate layers of wire net and rubber and is useful in vehicle transmissions.
Another important consideration in the design of reinforced tubing devices is the need for adequate tubing resilience (i.e., resistance to permanent deformation, kinking, and buckling under stress). Also, it may be desirable that the reinforced tubing be highly flexible for certain applications, such as for providing a conduit for fluid flow. It may also be desirable that the tubing retain sufficient strength to function effectively as a torque transmitter.
In one application, such as intravascular catheters used to advance medical devices to the arterial system surrounding the heart, there is a need for the catheter to be flexible but nevertheless, also exhibit a certain amount of stiffness so that the catheter may be advanced through various twists and turns presented by the arterial system. Also, while the body of the catheter must exhibit the desired characteristics of flexibility and stiffness, the catheter lumen must have a low friction surface so that an inner catheter or guidewire can be easily advanced through the lumen. An example of one such device which can be used in medical applications and discloses an invention which exhibits the characteristics of flexibility and stiffness is U.S. Pat. No. 5,538,510 which employs coextruded tubular members to achieve the desired results. The disadvantage of this coextrusion invention is that the manufacturing process of this device is complex and has the potential for relatively thick walls and large profiles.
While each of the reinforced tubing devices discussed above can fulfill at least one of the above requirements, there is still a need for a single reinforced tubing device which can be used interchangeably in a variety of applications and which will simultaneously provide all or several of the characteristics mentioned above. To satisfy this need, the present invention recognizes that a reinforced tubing device can be provided which is relatively strong, flexible and thin walled, and which does not easily kink, permanently deform, or buckle under stress.
Accordingly, it is an object of the present invention to provide a thin walled reinforced tubing device which is both relatively flexible and strong.
It is a further object of the present invention to provide a reinforced tubing device that efficiently transmits translational and rotational motion without easily buckling, kinking, or permanently deforming.
Yet another object of the present invention is to provide a reinforced tubing device that yields a specific inner lumen configuration which reduces the overall internal contact area and thereby reduces the frictional drag imparted to objects passing through it.
Another object of the present invention is to provide a method of reinforcing a tubular member which can vary certain properties, such as flexibility, along the length of the tubing.
Another object of the present invention is to provide a method of fabricating flexible tubing from materials not known to have flexible characteristics or from materials with a relatively high modulus.
Another object of the present invention is to provide a tubular structure containing a multitude of protruding elements which, in response to bending or flexing stresses, modify their configuration rather than and thereby minimize significant elongation and compression of the base material.
Yet another object of the present invention is to provide a reinforced tubing with relatively a thin wall and maintaining the characteristics described in the above six paragraphs.
Another object of the present invention is to provide a reinforced tubing device which can be used in a wide variety of applications.
Yet another object of the present invention is to provide a reinforced tubing device that is easy to use and relatively cost effective to manufacture.